A REVIEW OF MODERN STEGANOGRAPHY TECHNIQUES

Steganography is the art and science of hiding secret information using a cover object. It is a better way of covert communication than cryptography in that when using the cryptography, it raises a suspicion to unintended receiver that a secret communication is taking place whereas staganography hides the fact that a secret communication has taken place. Steganography has been in use since ancient times. Modern day steganography uses digital techniques involving digital media as cover objects like image, audio, video etc. Digital image has been a popular medium for steganography. This paper reviews the various techniques used for image steganography. Steganography techniques can be broadly categorized as Spatial domain and Transform domain. Popular spatial domain techniques are LSB substitution, Patchwork and Bit plane Complexity Segmentation (BPCS). The Transform domain techniques mainly consist of Discrete Cosine Transforms (DCT), Discrete Fourier Transforms (DFT) and Discrete Wavelet Transforms (DWT) based techniques. Steganography combined with cryptography can provide multilayer security and ruggedness in today’s scenario of unsecured public networks like internet.